Choosing a practical screening instrument to identify patients at risk for diabetic foot ulceration.
OBJECTIVE
To evaluate the sensitivity and specificity of 3 sensory perception testing instruments to screen for risk of diabetic foot ulceration.


METHODS
This case-control study prospectively measured the degree of peripheral sensory neuropathy in diabetic patients with and without foot ulcers. We enrolled 115 age-matched diabetic patients (40% male) with a case-control ratio of approximately 1:3 (30 cases and 85 controls) from a tertiary care diabetic foot specialty clinic. Cases were defined as individuals who had an existing foot ulceration or a history of a recently (< 4 weeks) healed foot ulceration. Controls were defined as subjects with no foot ulceration history. Using receiver operating characteristic analysis, we evaluated the sensitivity and specificity of 2 commonly used nephropathy assessment tools (vibration perception threshold testing and the Semmes-Weinstein 10-g monofilament wire system) and a 4-question verbal neuropathy score to evaluate for presence of foot ulceration.


RESULTS
A vibration perception threshold testing using 25 V and lack of perception at 4 or more sites using the Semmes-Weinstein 10-g monofilament wire system had a significantly higher specificity than neuropathy score used. The neuropathy score was most sensitive when 1 or more answers were affirmative. When modalities were combined, particularly the monofilament wire system plus vibration perception threshold testing and the neuropathy score plus the monofilament wire system, there was a substantial increase in specificity with little or no diminution in sensitivity.


CONCLUSIONS
The early detection of peripheral neuropathy or loss of "protective sensation" is paramount to instituting a structured treatment plan to prevent lower extremity amputation. The results of our study suggest that all 3 sensory perception testing instruments are sensitive in identifying patients at risk for ulceration. Combining modalities appears to increase specificity with very little or no diminution in sensitivity.
Armstrong
D G
DG
Department of Orthopaedics, University of Texas Health Science Center, San Antonio, Tex., USA.
Lavery
L A
LA
Vela
S A
SA
Quebedeaux
T L
TL
Fleischli
J G
JG
D000328:Adult; D016022:Case-Control Studies; D017719:Diabetic Foot / Q000453:epidemiology* / Q000209:etiology; D003929:Diabetic Neuropathies / Q000150:complications; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D012306:Risk; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires; D014110:Touch; D014732:Vibration